1. Field of the Invention
The present invention relates generally to broadcast message filtering, and, in particular, to an apparatus and method for reducing power consumption of a communication terminal by implementing a response to a broadcast message forwarding to a communication terminal complying with a specific wireless protocol.
2. Description of the Related Art
Mobile communication systems have rapidly evolved since their introduction. At present, mobile communication systems are attempting convergence with a communication system based on a heterogeneous wireless technology.
An example of Unlicensed Mobile Access (UMA) is shown in FIGS. 1A and 1B, which, illustrate a conventional network using UMA.
Referring to FIG. 1A, in the UMA, a UMA Network Controller (UNC) 101 provides access between a communication system based on a different wireless technology (e.g., Wi-Fi) and a mobile communication system. Signaling of the UMA can use signaling of a mobile communication system. A communication terminal can selectively use a mobile communication system or a different wireless technology. In detail, in the UMA system, a communication terminal can automatically detect an area based on a different wireless protocol and then connect with Internet through the UNC 101. GSM voice call and all GSM/GPRS data application service can be provided to a communication terminal 102.
Conventional wireless communication technology, including Wi-Fi, has been applied to various digital home equipment, such as notebook computers, and allows for communication and Internet connection between them. Most equipment is commonly used in a home or an office and is directly connected to an external power supply and thus is to some degree, independent from power consumption constraints. However, as such a wireless communication technology is applied to a communication terminal, the amount of consumption power will greatly influence stand-by time. Thus, power consumption savings in a communication terminal is becoming a key technology.
In Wi-Fi systems, a communication terminal receives only a beacon channel at a predetermined Traffic Indication Map (TIM) period using a power save mode without receiving all traffic from the Access Point (AP). Thus, it can check whether there is information to be received using information on the beacon channel.
In this case, AP stores operation information in an internal buffer and involves transmission information on a target communication terminal in the beacon channel. This method can reduce, though sometimes causing reception delay, power consumption because it does not perform unnecessary reception work compared to a method in which a communication terminal receives all data.
Wireless fidelity MultiMedia (WMM), which evolved from Wi-Fi, can reduce power consumption using an Unscheduled Automatic Power Save Delivery (U-APSD) technology. The U-APSD, which is a method for enabling a periodic connection to the AP using a timer during voice telephony on the basis of a feature of periodic transmission/reception requirements, can increase available telephony time. In other words, the U-APSD enables a communication terminal to implement downlink scheduling and receive data from AP, on the basis of a repeated pattern of a beacon period. AP performs buffering for a communication terminal at a predefined beacon period and then transmits a buffered packet to a communication terminal awaken at its own period.
In a standby mode, a communication terminal identifies and receives a beacon channel at the TIM period and periodically receives even broadcast data at a Delivery Traffic Indication Message (DTIM) period. The broadcast data is used even when various types of equipment, such as notebook computers or Personal Computers (PC), exchange data with each other as in FIG. 1A. The broadcast data is used when they are assigned an Internet Protocol (IP) address using Dynamic Host Configuration Protocol (DHCP). FIG. 1B shows that various kinds of equipment that communicate with each other or are provided with Internet an service through AP installed in a home or an office.
An increase in the number of equipment results in an increased number of broadcast messages that the equipment should receive and respond to. For example, after a new notebook computer is assigned an IP address from a DHCP server, it should check whether there different equipment exist using the same IP address in a sub-network. For this, the notebook computer should inquire about whether all of the different equipment use the same IP address by a broadcast message. Equipment using the same IP address, if any, should respond to the broadcast message. Broadcast traffic such as the broadcast message does not greatly influence equipment using an external power supply, but can cause undesired power consumption and reduce stand-by time in equipment that is battery powered.
Accordingly, a demand exists for an apparatus and method for processing broadcast data to reduce power consumption and increase stand-by time.